While working with a version control system like git it is sometimes a good idea to create an independent branch. This article shows how to accomplish that. In this example I want to hold onto the documentation in a separate branch.
I assume, that you already created a repository and added various commits onto you master branch.

Prepare your ignore listNow its time to prepare for the repository. First, edit your .gitignore file and exclude the doc/ folder which you will be creating in the next step.

Create an orphan branch
Create a new independent branch with the git checkout option --orphan. The option is available since Git 1.7.2. Initially, you will have to remove the files that have been created in the working directory, but right after the branch is independent.
Now you can create a doc/ folder and create documentation files. In the end you can commit them to the repository as usual.